> Feel free to seek the advice of an attorney on taking the 5th on a tax form

> Feel free to seek the advice of an attorney

> seek the advice of an attorney

> an attorney

Are you an attorney?

> being asked XXXX doesn't amount to compelled admission of a crime, because XXXX isn't illegal

This is bad legal advice! Talk to a lawyer (before you talk to the IRS or any government investigatory agency), especially if it is your plan or intent to lie to the government or challenge their interpretation of a law and how it governs your behavior (the premise of OP).

Better advice: Seek tax or legal advice on HN. From anyone.